I have 100mm version and dumped the zoom for the 30x eyepiece for seawatching. Beware the tiny screws that hold the tripod attaching plate to the threads on mine shredded rendering it useless I now use a bean bag which is fine on the seawall or in a hide.
It is significantly worse in performance than my Opticron HR ED 80 not as bright, bit of colour fringing at times and not crystal clear at the edges but then it is significantly less expensive and overall I'm quite happy with it
It is significantly worse in performance than my Opticron HR ED 80 not as bright, bit of colour fringing at times and not crystal clear at the edges but then it is significantly less expensive and overall I'm quite happy with it